/**
 * Copyright 2011 ArcBees Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package vn.nichecafe.client.ui;

import com.google.gwt.core.client.GWT;
import com.google.gwt.uibinder.client.UiBinder;
import com.google.gwt.uibinder.client.UiField;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.Hyperlink;
import com.google.gwt.user.client.ui.Widget;
import com.gwtplatform.mvp.client.Tab;
import com.gwtplatform.mvp.client.TabData;
import com.gwtplatform.mvp.client.proxy.Gatekeeper;

/**
 * A {@link BaseTab} styled with rounded upper corners and meant to be contained
 * in a {@link RoundTabPanel}. This tab can be protected so that it is only
 * displayed when a given {@link Gatekeeper} can allow access. If a {@code null}
 * {@link Gatekeeper} is used then the tab is always accessible.
 * 
 * @author Philippe Beaudoin
 */
public class Menu extends Composite implements Tab {

	@UiField
	Hyperlink hyperlink;
	
	private final float priority;

	public Menu(TabData tabData, Gatekeeper gatekeeper) {
		this.gatekeeper = gatekeeper;
		initWidget(binder.createAndBindUi(this));
		setText(tabData.getLabel());
		this.priority = tabData.getPriority();
	}

	@Override
	public Widget asWidget() {
		return this;
	}

	@Override
	public float getPriority() {
		return priority;
	}

	@Override
	public String getText() {
		return hyperlink.getText();
	}

	@Override
	public void setTargetHistoryToken(String historyToken) {
		hyperlink.setTargetHistoryToken(historyToken);
	}

	@Override
	public void setText(String text) {
		hyperlink.setText(text);
	}

	interface Binder extends UiBinder<Widget, Menu> {
	}

	// TODO Once we use assisted injection in {@link SimpleTabPabel}, then
	// inject the binder.
	private static final Binder binder = GWT.create(Binder.class);

	private final Gatekeeper gatekeeper;

	/**
	 * Checks whether or not the current user has the right to access this tab.
	 * By default, all tabs can be accessed.
	 * 
	 * @return {@code true} if the user can access this tab, {@code false}
	 *         otherwise.
	 */
	public boolean canUserAccess() {
		return gatekeeper == null || gatekeeper.canReveal();
	}

	@Override
	public void activate() {
		hyperlink.addStyleName("current");
	}

	@Override
	public void deactivate() {
		hyperlink.removeStyleName("current");
	}

}
